Safety cutoff for a power tool or other device

ABSTRACT

A cutoff system for a power tool or other device includes a receiver and a transmitter, the receiver being configured to electrically couple to a power source and to a power tool or other device, the transmitter is configured to transmit a communication signal to the receiver, and the receiver is further configured to transmit electrical power from the power source to the power tool or other device only when the receiver receives the communication signal from the transmitter.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/463,687, filed on Mar. 20, 2017 and entitled “Safety Cutofffor a Power Tool or Other Device,” which is a continuation of U.S.patent application Ser. No. 15/248,371, filed on Aug. 26, 2016, entitled“Safety Cutoff for a Power Tool or Other Device,” which claims thebenefit of U.S. Provisional Patent Application No. 62/330,918, filed onMay 3, 2016 and titled “Safety Cutoff for a Power Tool or Other Device,”the entire contents of which are incorporated herein by reference intheir entirety.

BACKGROUND OF THE INVENTION

The present application relates to an automatic cutoff device fordisabling electrical current to a power tool or other device when theoperator is not within a certain proximity of the tool or other device.

Power tools, such as drills, saws, sanders, and the like, are generallyknown. Such tools are generally electrically powered, either through acorded connection to a wall outlet or with a battery connected to thetool for added portability. Electric power presents great benefits to anoperator in terms of the added energy the tool can be capable ofexerting compared to manual power, such as additional torque for a drillor faster movement of an electric sander, which allows an operator toperform tasks that may not be capable of performance throughhand-powered tools or may allow an operator to perform tasks faster orwith less exertion than with hand-powered tools.

However, traditional power tools are powered at all times when pluggedin or connected to a charged battery. The energy capable of exertion bypower tools can therefore be dangerous if a tools is unintentionallyactivated by a passerby, a child, or by the operator when his or herattention is directed elsewhere. Therefore, a need exists for anautomatic cutoff device that disables power to the power tool when theoperator is not within the proximity of the tool to prevent accidentalactivation of the tool.

BRIEF SUMMARY OF THE INVENTION

A cutoff system for a power tool or other device includes a receiver anda transmitter, wherein the receiver is configured to electrically coupleto a power source and to a power tool or other device, the transmitteris configured to transmit a communication signal to the receiver, andthe receiver is further configured to transmit electrical power from thepower source to the power tool or other device only when the receiverreceives the communication signal from the transmitter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe invention, will be better understood when read in conjunction withthe appended drawings. For the purpose of illustrating the invention,there are shown in the drawings embodiments which are presentlypreferred. It should be understood, however, that the invention is notlimited to the precise arrangements and instrumentalities shown. In thedrawings:

FIG. 1 is a front perspective view of a safety cutoff device for a powertool including a receiver, a power tool, an electrical outlet, and atransmitter in an open configuration in accordance with a firstpreferred embodiment of the invention;

FIG. 2 is a side elevational view of the transmitter of FIG. 1, shown ina closed configuration;

FIG. 3 is a front perspective view of a second embodiment of the safetycutoff device for a power tool, including a receiver, a power tool, abattery, and a transmitter; and

FIG. 4 is a schematic block diagram of the electrical componentsassociated with the receiver of the safety cutoff device of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Certain terminology is used in the following description for convenienceonly and is not limiting. Unless specifically set forth herein, theterms “a”, “an” and “the” are not limited to one element but insteadshould be read as meaning “at least one”. The words “right,” “left,”“lower,” and “upper” designate directions in the drawings to whichreference is made. The words “inwardly” or “distally” and “outwardly” or“proximally” refer to directions toward and away from, respectively, thegeometric center or orientation of the device and instruments andrelated parts thereof. The terminology includes the above-listed words,derivatives thereof and words of similar import.

It should also be understood that the terms “about,” “approximately,”“generally,” “substantially” and like terms, used herein when referringto a dimension or characteristic of a component of the invention,indicate that the described dimension/characteristic is not a strictboundary or parameter and does not exclude minor variations therefromthat are functionally the same or similar, as would be understood by onehaving ordinary skill in the art. At a minimum, such references thatinclude a numerical parameter would include variations that, usingmathematical and industrial principles accepted in the art (e.g.,rounding, measurement or other systematic errors, manufacturingtolerances, etc.), would not vary the least significant digit.

Referring to FIGS. 1-2, a first preferred embodiment of a safety cutoffsystem 1 is shown. The cutoff system 1 includes a receiver 10 and atransmitter 30. To demonstrate the cutoff system in use, FIG. 1 alsoshows a power tool 80 and an electrical outlet 90. One side of thereceiver 10 is preferably configured to plug into and draw power fromany common source of electrical power, such as a three-pronged walloutlet 90, an extension cord (not shown), and the like. The opposingside of the receiver 10 is preferably configured to receive and providepower to the end of the cord 82 of the power tool 80, the power beingdrawn from the electrical outlet 90 and passed through the receiver 10preferably with minimal loss.

The receiver 10 is in communication with a transmitter 30. Suchcommunication is preferably via the Bluetooth® protocol, but may be anyformat suitable for short-range wireless communication. The transmitter30 is configured to generally continuously or periodically send acommunication signal to the receiver 10. The receiver 10 is in turnconfigured to only provide power to the power tool 80 when it isreceiving the communication signal from the transmitter 30. If thereceiver 10 detects no signal from the transmitter 30 for apredetermined minimal time, such as if the transmitter 30 is moved to adistance beyond the maximum range from which it can communicate with thereceiver 10 (preferably approximately ten meters), the receiver 10 shutsoff power to the power tool 80 until the receiver 10 again detects thesignal from the transmitter 30. The transmitter 30 is powered by anysuitable portable powering means, such as by one or more AA batteries.In an alternative embodiment, the transmitter 30 may be configured as anapplication on a user's smart phone or similar device.

The transmitter 30 is preferably configured to include an arm 37attached to the transmitter 30 by a hinge 36. The hinge 36 is preferablyspring loaded such that the hinge 36 maintains the arm 37 generallyproximate to the transmitter 30 (as shown in FIG. 2) unless a user pullsthe arm 37 away from the transmitter 30 (as shown in FIG. 1). The arm 37is preferably configured such that it can be mounted on a user's belt,pocket, or other item of clothing with the spring loaded nature of thehinge 36 providing sufficient force to retain the arm 37 against theuser's belt, pocket, or other item of clothing. In use, the ability toattach the transmitter 30 to a user's clothing provides for the power tobe cut off from the power tool 80 if the user moves away from thereceiver 10, disrupting communication between the transmitter 30 andreceiver 10.

The transmitter 30 further preferably includes at least two electricalcontacts 34. One contact 34 is preferably located at a distal end 38 ofthe arm 37 and the other contact 34 is preferably located on the body ofthe transmitter 30. The transmitter 30 is preferably configured suchthat it does not transmit a communication signal to the receiver 10 ifthe contacts 34 are in engagement with one another. In use, the contacts34 provide for the function that the transmitter 30 does not transmit asignal, and therefore the receiver 10 does not provide power to thepower tool 80, unless the user retracts the arm 37 and preferably mountsthe transmitter 30 to an article of his or her clothing. If, during use,the transmitter 30 is dislodged from the operator's belt or clothing,the contacts 34 reengage with one another to prevent the communicationsignal from being sent by the transmitter 30 and power is cut off to thepower tool 80. Left alone, the contacts 34 are in contact with eachother and the power tool 80 does not receive power. The transmitter 30is preferably configured to be waterproof or water-resistant such thatit can withstand adverse operating conditions while mounted to anoperator's belt or clothing, such as in rain.

The receiver 10 and the transmitter 30 preferably each have statuslights 12, 32 which are configured to indicate whether the receiver 10and transmitter 30 are within close enough proximity to maintaincommunication. The status lights 12, 32 can be configured to only blinkwhen the receiver 10 is in communication with the transmitter 30, toblink green when the receiver 10 and transmitter 30 are in communicationand to blink red when the receiver 10 and transmitter 30 are not incommunication, or in any other fashion to suitably distinguish betweenthe in-communication and out-of-communication states of the receiver 10and transmitter 30. The receiver 10, the transmitter 30, or both arealso preferably configured to also have an audio alert system includingspeakers 15, 35 to indicate, in conjunction with the status lights 12,32 when the receiver 10 and the transmitter 30 are or are not incommunication. In another embodiment, the receiver 10, transmitter 30,or both may be configured to communicate with at least one externalaudio device, such as a walkie-talkie, to alert users when the receiver10 and transmitter 30 are in communication.

Referring to FIG. 4, circuitry 60 of the receiver 10 is shown inschematic block diagram form. The circuitry 60 includes an antenna 62 tofacilitate communication with the transmitter 30 and with the statuslight 12. The circuitry 60 preferably includes an amperage meter 64capable of measuring the current received from the electrical outlet 90or source of electrical power and drawn by the power tool 80. Theamperage meter 64 is preferably configured to detect whether the powertool 80 or other device is drawing more current than would usually berequired by the power tool 80, such as in the case of a short circuit.In such cases, the receiver 10 is preferably configured to cut off powerto the power tool 80. The circuitry 60 also preferably includes a surgeprotector 68 capable of regulating the power provided to the power tool80 should the circuitry 60 detect an unexpected voltage spike from theelectrical outlet 90 or source of electrical power.

The circuitry 60 also preferably includes a current leakage detector 66capable of detecting current leakage. In the event that the currentleakage detector 66 detects current leaked to a ground that exceeds apredetermined amount, the current leakage detector 66 cuts off power tothe power tool 80. This functionality aids in the desired goal of safetywhen using power tools or other devices by cutting off power anddisabling the power tool 80 or other device in the event that power fromthe tool leaks from the power tool 80 to the operator, causing apotentially harmful electric shock to the operator. The current leakagedetector 66 can be a common ground fault current interrupter, leakagecurrent detector interrupter, equipment ground-fault protective device,appliance leakage current interrupter, immersion detection currentinterrupter, or any other type of current leakage detector 66 that canperform the described functionality and withstand the normal operatingconditions of the receiver 10.

Referring now to FIG. 3, a second preferred embodiment of a safetycutoff system 101 is shown. The second preferred embodiment preferablyincludes a receiver 110, and a transmitter 130. To demonstrate use ofthe cut off system 101, FIG. 3 also shows a power tool 180 and a battery184. The second preferred embodiment is configured for use with abattery powered power tool 180, such as a drill. Power tools 180 arecommonly available in a cordless configuration and powered by arechargeable 12 Volt, 18 Volt, 20 Volt, or other voltage battery 184.Typically, the battery 184 is mounted directly to the power tool 180 andis easily removable by a user to recharge the battery 184 and optionallyattach a different battery 184. In the second preferred embodiment ofthe cutoff system 101, the receiver 110 is configured to mount to thepower tool 180 in place of the battery 184, while the opposing side ofthe receiver 110 is configured to receive the battery 184 and pass powerthrough to the power tool 180. In use, the receiver 110 of the secondpreferred embodiment operates in the same fashion as the receiver 10 ofthe first preferred embodiment, in that it does not transmit power fromthe battery 184 to the power tool 180 unless the transmitter 130 iswithin a suitable distance to engage in communication. In an alternateembodiment (not shown), the receiver 110 may be built into the battery184. The receiver 110 and transmitter 130 preferably include statuslights 112, 132 and an audio alert system including speakers 115, 135just as in the first preferred embodiment.

It will be appreciated that the cutoff system 1, 101 may be used withdevices other than a power tool 80, 180 for performing the abovedescribed cutoff function and that the present invention is not limitedto use with power tools. For example, and by no means limiting, thecutoff system 1, 101 may be used to cutoff power when the transmitter30, 130 is not within range of a receiver 10, 110 mounted to anautomobile, garbage disposal, space heater, air conditioner, electricstove, lawn mower, factory tools, industrial machines, surge protector,extension cord, power strip, wall outlet or receptacle, universalrechargeable battery, or any other device which utilizes electricity andfor which there may be a desire to add an automatic cutoff function.

It will be appreciated by those skilled in the art that changes could bemade to the embodiment described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiment disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the present disclosure.

We claim:
 1. A detachable adapter for an electrical power tool, thedetachable adapter having a first location to selectively attach to theelectrical power tool and a second location to selectively attach to aremovable battery, the detachable adapter comprising: a receiver mountedwithin the adapter configured to: (i) receive a first communicationsignal generated by a transmitter; (ii) to command or allow thedetachable adapter to transmit electrical current from the battery tothe electrical power tool when the receiver detects the firstcommunication signal; and (iii) to interrupt electrical current from thebattery to the electrical power tool when the receiver does not detectthe first communication signal; and a current leakage detector mountedwithin the adapter configured to interrupt electrical current from thebattery to the electrical power tool when current leakage is detected.2. The detachable adapter of claim 1, wherein the adapter furthercomprises a status light configured to indicate whether a firstcommunication signal broadcast by a transmitter is detected.
 3. Thedetachable adapter of claim 1, wherein the adapter further comprises aspeaker configured to indicate whether the first communication signal isdetected.
 4. The detachable adapter of claim 1, wherein the adapter isfurther configured to halt transmission of electrical current when thecurrent drawn by the electrical power tool exceeds the normal operatingcurrent of the power tool.
 5. The detachable adapter of claim 1, furthercomprising a communication device, wherein the adapter is configured totransmit a second communication signal to the communication device toindicate whether the first communication signal is detected.
 6. Thedetachable adapter of claim 5, wherein the communication device is asmartphone.
 7. A detachable adapter for an electrical power tool, thedetachable adapter having a first location to selectively attach to theelectrical power tool and a second location to selectively attach to aremovable battery, the detachable adapter comprising: a receiver mountedwithin the adapter configured to: (i) receive a first communicationsignal generated by a transmitter; (ii) to command or allow thedetachable adapter to transmit electrical current from the battery tothe electrical power tool when the receiver detects the firstcommunication signal; and (iii) to interrupt electrical current from thebattery to the electrical power tool when the receiver does not detectthe first communication signal; and an amperage meter mounted within theadapter configured to interrupt electrical current from the battery tothe electrical power tool when the power tool draws current exceeding apredetermined value.
 8. The detachable adapter of claim 7, wherein theadapter further comprises a status light configured to indicate whethera first communication signal broadcast by a transmitter is detected. 9.The detachable adapter of claim 7, wherein the adapter further comprisesa speaker configured to indicate whether the first communication signalis detected.
 10. The detachable adapter of claim 7, wherein the adapteris further configured to halt transmission of electrical current whencurrent leakage is detected.
 11. The detachable adapter of claim 7,further comprising a communication device, wherein the adapter isconfigured to transmit a second communication signal to thecommunication device to indicate whether the first communication signalis detected.
 12. The detachable adapter of claim 11, wherein thecommunication device is a smartphone.
 13. A detachable adapter for anelectrical power tool, the detachable adapter having a first location toselectively attach to the electrical power tool and a second location toselectively attach to a removable battery, the detachable adaptercomprising: a receiver mounted within the adapter configured to: (i)receive a first communication signal generated by a transmitter; (ii) tocommand or allow the detachable adapter to transmit electrical currentfrom the battery to the electrical power tool when the receiver detectsthe first communication signal; and (iii) to interrupt electricalcurrent from the battery to the electrical power tool when the receiverdoes not detect the first communication signal; and a status lightconfigured to indicate whether the communication signal is beingdetected by the receiver.
 14. The detachable adapter of claim 13,wherein the adapter further comprises a speaker configured to indicatewhether the first communication signal is detected.
 15. The detachableadapter of claim 13, wherein the adapter is further configured to halttransmission of electrical current when the current drawn by theelectrical power tool exceeds the normal operating current of the powertool.
 16. The detachable adapter of claim 13, wherein the adapter isfurther configured to halt transmission of electrical current whencurrent leakage is detected.
 17. The detachable adapter of claim 13,further comprising a communication device, wherein the adapter isconfigured to transmit a second communication signal to thecommunication device to indicate whether the first communication signalis detected.
 18. The detachable adapter of claim 17, wherein thecommunication device is a smartphone.